Pekpetuaii caiendab



July 31, 192s. 1,678,834"

' G. TILDEN PERPETUAL CALENDAR FiledA June 5, 1926 Patented July 31,1928.

GALEN Tinnen,

or* AMES, IOWA.

PERPTUAL CALENDAR.

Application filed Jane 5,y

The object of my invention is to provide a perpetual calendar having anumber of advantageous features.

More particularly, it is my object to provide such` a vcalendar havingthereon means for indicating Ithe first Vninety-nine years of foursuccessive centuries, the indicating characters representing' the yearsbeing arranged in groups to represent years separated by twenty-eightyear periods, each of said groups being also arranged for reference toother means for locating the weekly calendars for the respective years.v

Another purpose, is to provide in. such a calendar, groups of charactersindicating the monthly calendar for groups of years separated bytwenty-eight year periods.v

Still another purpose is to provide in suchl a calendar a series ofseven monthly calendars.

Generally speaking, it is my purpose to provide all of this matter soarranged andV associated together, as to be particularly convenientforreference, and inthat connectionI show the material arranged forconvenience/on discs suitably mounted on a common support. With theseand other objects in view, my invention consists in the construction',lar rangement and combination of the various parts of my perpetualcalendar`,rwhereby the objects contemplated are attained, as hereinaftermore fullyk set forth, pointed out in my claims, and illustrated in theaccompanying drawings, in which: Figure 1 is a rear elevation of aperpetual calendar embodying my invention.

Figure 2 is a detail, sectional view of the same takenv on the line 2 2of Figure 1.

Figure 3 is a front elevation ofy my calendar.

Figure L1 is a plan view of the face of one of the discs; andy Figure 5is a plan view of the face ofv another disc. y

In the accompanying drawings, I have used the reference numerals lll-and11v to indicate generally the front and rear mem? bers of a casing,which may be connected together in any suitable wayfor supporting' themin relation to permit the discs herein-l after described tobe mountedbetween them. In Figure 4r, I have shown the face of a' disc 12 havingarranged thereon, preferably in spiral form, numbers from 1f to 99repre-y senting the rst ninety-nine Vyears of a cen- 192'6. serial No.114,017.

`Arranged in a radial column oppositey each of the letters on the disc13 are'fdouble rows of indicating characters, representing monthlycalendars.

The discs 12 and 13 are mounted between the members 10 and 11forrotation.

In the member 101' is a sight opening 14C,

elongated radially with relation' to the disc'- 12, through which anyoneof the radial columns of characters onthe disc 12 may.v

be made visible by properly rotating that disc. f

-Adjacent to thev sight opening 14 are indicating characters, such asFor any cen- Adjacent to the sight opening 14, there are arranged on themember 10, characters -4 15 for indicating four centuries. rlhecharactersy 19 forv indicating the twentieth century are opposite theinnermost cir-cum'- ferential row of letters on the disc'12, thecharacters 18 lopposite the next outer row ofletters, and so on;

It thus follows that if the disc 12 be rotated, forbringing any radialcolumn to position where it may be. seen throughthe opening 14, certainnumbers ywill be visible. As shown in Figure 3, these numbers lead'- ingfrom the inside, radially outwardly, are 08, 36, 64, and 92 f l If theuserof thecalendar desires to find a: monthly calendar therefore for anyyear in the 17th to the 20th centuries, represented .by4 any of thosenumbersY just mentioned', he looks' for the letter exposed lthrough ythe lsight opening opposite the number indicating thecentury underconsideration;

For instance, if the year, for which' a monthly calendar is'jdesired, isthe year 1908, the'disc 12 is'rotat'ed until the numbers U08 are exposedthrough the sight opening 14, and then by'following down the sightopening, it will be noted that themonthly calendar isv indicated by theletter L,

opposite the number 19 indicating the 20th century.

. If it be remembered that the calendar for each successive four hundredyears is .the

same, it will be observed that this is a perpetual calendar. j l Themonthly calendar for the last year in each century may be found in thefollowingk manner:

n the member 10 are characters indicating the years 1700,1800, 1900, and2000, and opposite these year indicating characters are letters G, C, A,and

N representing calendar groups in the same way as do the letters on thedisc 12;

The disc 13 is mounted between lthe members and 11. The member 10 has anelongated sight opening 16 through which any of the radial columns onthe disc 13 lmay be n certain year the monthly calendar group in-Ldicating letter G has appeared through the sight opening 111, then thedisc 13 is rotated until the letter Gr appears through the sight opening16, whereupon the number opposite each monthly indicating means on themember 10 adjacent to the sight opening 16 will represent the calendarfor such month.

It will be noted that thegroups of monthly calendar indicatingcharacters on the disc 13 are arranged in radial columns for commonyears and leap years.

I provide also a disc 17 having arranged in a radial manner thereonseven monthly calendars for months beginning respectively on thedifferent days of the week.

Following the example referred to in connection with the explanation ofthe disc 13, if for a given year the monthly calendar indicating letterGr has been used, then when the disc 13 is rotated until G appearsthrough the sight opening '16, it will be found that the month of Mayfor example in the year under consideration is a month represented bycalendar No. 7 in which the month begins on the last day of the week,to-wit, Saturday. j i

The Adisc 17 may be rotated until the appropriate monthly calendar No. 7is visible through a sight opening 18 in the member 11. When thatcalendar is exposed, it will be easy to ascertain upon what day of theweek any day of the month fell.

Adjacent to the opening 18 are characters representing the days of theweek.

i I preferably mount a small disc 19 for rotationbetween the members 10and 11. The disc 19 may be mounted concentrically with the disc 17 ifdesired.

ArrangedV Vcircumferentially around the disc 19 are charactersrepresenting the various months and the number of days in such months.Such a seti ofL characters for any month may be exposed through thesight' opening 20 by proper rotation ofthe disc 19,

for thus readily determining the number ofv mounted relative to saidsupport kand bearing ninety-nine characters successively arranged toindicate ninety-nine years of a century and arranged in "rows andcolumns, each of said columns'also including index characters applicableto various units of a quarcentenary group, a second member.

movably mounted relative to the support and bearing columns ofcharacters indicating monthly calendars, each of the last named columnsalso including one ofthe in-v dex characters of the first movable membercharacters on said support indicating a quarcentenary group with whichkthe index characters of the columns `of the first movable member may bebrought selectively into juxtaposition, a column of characters on saidsupport representing the months of the year with which the columns ofthe second named movable member may 'be brought selectively Vintojuxtaposition tol designate the appropriate monthly calendarto be usedas indicated bythe associated index character, .and a group of monthlycalendars carried by said support and each bearing an index charactercorresponding to one of the characters carried by the second movablemember.

2.1n a calendar of the character described, a support, a member'movably` mounted relative to said support and bear'- ingninety-nine.characters successively arill! ranged to indicateninety-nine years of Ya century and arranged in rows and columns, eachofsaid columns also including index characters applicable to variousunitsof a quarcentenary group, a second memberv movably mountedfrelative touthe support. and I bearing columns of characters indicating monthlycalandars for both leap years and` common years, each of the lastnamedcolumns .also including one ofthe index characters ofv the lirst movablemember, characters on said support indicating a year with which'thecolumns of the second' named movable member may be brought se*-lectively into juxtaposition to designate the appropriate monthlycalendar to be used as indicated by the associated index character, anda plurality of monthly calendars for both leap years and common yearscarried by said support and each bearing an index charactercorresponding to one of the characters carried by the second movablemember.

3.111 a calendar of the character de-r scribed, a support, a membermovably mounted relative to said support and bearing ninety-ninecharacters successively arranged to indicate ninety-nine years of acentury and arranged in rows and columns, each of said columns alsoincluding index characters applicable to various units of aquarcentenary group, a second member movably mounted relative to thesupport and bearing columns of characters indicating monthly calendars,each of the last named columns also including one of the indexcharacters of the first movable member, characters on said supportindicating a quarcentenary group with which the index characters of thecolumns of the lirst movable member may be brought selectively intojuxtaposition, index characters on said support indicating the onehundredth year of each century of the group, a column of characters onsaid support representing the months of the year and with kwhich thecolumns of the second named movable member may be brought selectivelyinto juxtaposition to designate the appropriate monthly calendar to beused as indicated by the associated index character, and a plurality ofmonthly calendars carried by said support and each bearing an indexcharacter corresponding to one of the vcharacters carried by the secondmovable member.

4. In a calendar of the character described, a support, a member movablymounted relative to said support and bearing characters arranged in rowsand columns to indicate years, each of said columns also including indexcharacters applicable to various units of a group of centuries, a

thereon,

second member movably mounted relativeto the support and bearingcolumns'of characters indicating :monthly calendars, each of the 'lastnamed columns also including one of the index characters of the irstmovable member, charactersy on said support indicating a century groupwithwhich the index s charactersof the columns ofthe lirst movablemember may be brought selectively into juxtaposition, a column ofcharacters on said support representing the months of the year withwhich thecolumns of the second named movable member may be broughtselectively into juxtaposition to designate the appropriate monthlycalendar to be used as indicated by the associated index character, anda plurality of monthly calendars carried by said support and eachbearing an index character corresponding to one of the characterscarried member. y

5. In a calendar of the character described, a support, a member movablymounted relative to said support yand having thereon, charactersrepresenting years of a century,

by the second movable f said yearly characters being arranged in rowsand columns with they characters of each column twenty-eight yearsapart, each of said columns 'also including index characters applicableto various units of a group of centuries, a second member movablymounted relative to the support and having characters indicating monthlycalendars, each of the last named columns also including one of theindex characters of the first movable member, characters on said supportindicating a plurality of centuries, with which century characters theindex characters of the first movable member may be brought selectivelyinto juxtaposition, a column of characters on said support representingthe months of the year and With which the columns of the second movablemember may be brought selectively into juxtaposition to designate theappropriate monthly calendar to be used as indicated by the associatedindex character, and a Lplurality of monthly calendars each bearing anindex character corresponding to one of the characters carried by thesecond movable member.

Des Moines, Iowa, June l, 1926.'

